This layout is 4' 4": by 8'. It needs the extra inches to accommodate the track's extended width. By wiring the sidings as blocks, you can run a train and motorized unit (such as a trolley) at the same time. .
(15) MTH 40-1001 10 inch straight
(12) MTH 40-1002 O-31 curve
( 4) MTH 40-1005 O31 lefthand switch
( 3) MTH 40-1004 O31 righthand switch
( 1) MTH 40-1024 bumper
Total of 35 pieces
The extended top siding can allow running of two trains at once. Note that the inner oval has had to be reconfigured.
(19) MTH 40-1001 10 inch straight
(10) MTH 40-1002 O-31 curve
( 4) MTH 40-1005 O31 lefthand switch
( 3) MTH 40-1004 O31 righthand switch
( 1) MTH 40-1024 bumper
( 1) MTH 40-1012 5.5 inch half straight
Total of 38 pieces
The right side is expanded. Again, along with the added siding, the layout itself has had to be reconfigured
(18) MTH 40-1001 10 inch straight
(12) MTH 40-1002 O-31 curve
( 5) MTH 40-1005 O31 lefthand switch
( 4) MTH 40-1004 O31 righthand switch
( 1) MTH 40-1024 bumper
( 2) MTH 40-1012 5.5 inch half straight
( 1) MTH 40-1018 3.5 in straight
Total of 43 pieces
Now we have two complete loops, which allows us to run two full trains simultaneously.
(19) MTH 40-1001 10 inch straight
(14) MTH 40-1002 O-31 curve
( 6) MTH 40-1005 O31 lefthand switch
( 5) MTH 40-1004 O31 righthand switch
( 1) MTH 40-1024 bumper
( 3) MTH 40-1012 5.5 inch half straight
( 1) MTH 40-1018 3.5 in straight
( 1) MTH 40-1017 4.25 in straight
Total of 50
Another layout using the longer right siding.
(19) MTH 40-1001 10 inch straight
(14) MTH 40-1002 O-31 curve
( 5) MTH 40-1005 O31 lefthand switch
( 4) MTH 40-1004 O31 righthand switch
( 1) MTH 40-1024 bumper
( 1) MTH 40-1012 5.5 inch half straight
( 1) MTH 40-1017 4.25 in straight
Total of 45 pieces